1. Field of the Invention
The present invention relates to laser processing technology, and particularly to laser processing technology which excels in mass production.
2. Related Art
As processing techniques of removing a film formed on a substrate or perforating a substrate, there is employed a method of applying a plurality of beams on one point with a target in a stationary condition. However, in such a method, since processing is performed to each point, in a case where there are a great number of points to be processed, shifting and stopping (acceleration and reduction of speed) of the target is repeated per point to be processed, an enormous period of time is required for processing.
On the other hand, there is a method whereby a light beam emitted from a laser generator is branched out to a plurality of light beams to shorten the processing time. Yet, there is a limit to the number of points branched toward due to an output limit of the laser generator. Hence, in the case of a substantial number of points to be processed, no appreciable effect is obtained. There is also a case of scattering due to branching.
To solve such output problem, Japanese Unexamined Patent Publication No. 2002-263876 employs two units of the laser generator in an overlapping manner for increasing laser intensity. Nevertheless, when using a plurality of laser generators in this manner, it is difficult to carry out adjustments to correct slippage of optical axes of the laser generators.
Further, it is conceivable to use a plurality of units of laser generators, without branching the light beam, such that one beam may be generated per laser generator. In this case, it is difficult to carry out adjustments and maintenance of pitch accuracy among the beams.
Still further, use of a plurality of laser generators increases equipment cost, thus leading to a rise in the processing cost of a product.
On the other hand, in the case of using the photolithographic process through mask projection, the time for processing is long and cost is high, hence, it is not suitable for processing large-sized substrates.
Accordingly, it is an object of the present invention to provide laser-processing technology which excels in mass production.